This PR moves us from the xteink openx4 SDK to the freeink sdk from
https://freeink.org. Out of the box there are NO changes needed in the
firmware to support this swap, it all magically works as is. However as
we support more than just the x3/x4 devices, this sdk allows us to pass
env vars into the build commands to include support for other devices.
As support for new hardware such as touch screens and bluetooth are
added the xteink builds decide at compile time if the libraries are used
or not. For example right now the freeinkui and icons libraries are in
the platform.io file but as they are not used anywhere, they won't be
included in the final build. Once the touch branch and sd themes branch
are merged in this sdk is required for them to function correctly. All
the docs for freeink are available at freeink.org/docs. x4/x3 is a
single binary build unlike other devices that will build unique binaries
for each device. Eventually we will want to remove a lot of the manual
isx3 type stuff from our firmware and go through the boardsupport api
the sdk provides as it will generalize everything into one common system
that any device can support. The upcoming touch branch does a lot of
this for us but this initial PR is JUST to get the sdk swapped over
without any code changes to show seamless integration without any
regressions.
## Summary
* **What is the goal of this PR?** Update project documentation to match
the current master implementation for cache formats, i18n, file
transfer/web server workflows, SD-card fonts, and root user-facing docs.
* **What changes are included?** Refreshes `book.bin`/`section.bin` docs
for v6/v25, updates File Transfer/Calibre/WebDAV/API docs, documents 24
UI languages and JSON language persistence, updates root
README/USER_GUIDE cache and network details, and syncs the tracked
CLAUDE skill doc cache-version notes.
## Additional Context
* Docs-only change. Verified with `git diff --check origin/master..HEAD`
and stale-reference greps for old cache versions, removed i18n APIs, old
WiFi screen wording, and raw `Serial.printf` examples. No firmware build
was run.
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**NO**_
### Summary
This PR introduces a lightweight contributor onboarding docs section
under `docs/contributing/` and improves local formatting ergonomics for
first-time contributors.
The goal is to make CrossPoint easier to contribute to for software
developers who are new to embedded systems (like me), while keeping
onboarding modular and aligned with existing project docs.
### What changed
- Added contributor docs hub: `docs/contributing/README.md`
- Added focused onboarding pages:
- `docs/contributing/getting-started.md`
- `docs/contributing/architecture.md`
- `docs/contributing/development-workflow.md`
- `docs/contributing/testing-debugging.md`
- Linked contributor docs from `README.md` for discoverability
- Expanded architecture documentation with Mermaid diagrams
- Improved `bin/clang-format-fix`:
- prefers `clang-format-21` when available
- validates formatter version and fails fast with a clear message if too
old
- handles missing positional arg safely
- Updated docs to explain common `clang-format` setup/version issues and
install paths (including fallback steps when `clang-format-21` is
unavailable in default apt sources)
### Why
- There was no dedicated contributor onboarding path; first-time
contributors had to infer workflow from multiple files.
- New contributors (especially from non-embedded backgrounds) need a
clear mental model of architecture, runtime flow, and debugging process.
- Local formatting setup caused avoidable friction due to clang-format
version mismatch (`.clang-format` expects newer keys used in CI).
- The updates make contribution setup more predictable, reduce
onboarding confusion, and align local checks with CI expectations.
### Additional context
- No firmware behavior/runtime logic was changed; this PR focuses on
contributor experience and tooling clarity.
---
### AI Usage
> Did you use AI tools to help write this code?
Yes, I used AI tools to assist with generating the documentation. I then
manually reviewed, tested, and refined the code to ensure it works
correctly. please feel free to point out any discrepancies or areas for
improvement.
Justin Mitchell